A Comparison of Four Mower Conditioners on Drying Rate and Leaf Loss in Alfalfa and Agrass

Mechanical conditioning of forage can be accomplished by passing the crop through fluted intermeshing rolls or by passing the crop over the tines of an impeller rotor. Three impeller conditioners and one intermeshing roll conditioner were compared in field experiments. The impeller conditioners differed on the type of tine used on the rotor. Hood position and impeller speed were the two adjustments made on all impeller conditioners. The linear load on the rolls was the only adjustment made on the intermeshing roll conditioner. The effect of the conditioning mechanisms and their adjustments on drying rate and leaf loss in alfalfa and grass crops was measured. Comparisons were made exclusively among impeller conditioners using all adjustment combinations and among all machines with specific aggressive and nonaggressive adjustments selected. In alfalfa, among impeller conditioners exclusively, the fast rotor speed caused about 7.3% leaf loss, which was 1.1 percentage point greater than the leaf loss caused by the slow rotor speed. With respect to hood position, the maximum average leaf loss was 6.77% and varied by less than 0.1 percentage point. Incidentally, in the first day of drying, alfalfa conditioned with the fast impeller speed exhibited a 3% greater drying rate constant than the drying rate constant of alfalfa conditioned with the slow impeller speed. In the first day of drying, grass conditioned with the fast impeller speed exhibited a 13% greater drying rate than the drying rate of grass conditioned with the slow impeller speed. In addition, drying rates in alfalfa varied less than 8% and drying rates in grass varied less than 10% in the first day of drying with respect to hood position. When comparisons were made exclusively among impeller conditioners, statistically significant differences in drying rate and leaf loss were only exhibited between the fast and slow impeller speeds. In the first day of drying, forage (both grass and alfalfa) conditioned by aggressively-set impeller machines exhibited drying rates 23 to 63% greater than drying rates of forage conditioned by the aggressively-set intermeshing roll conditioner. Also in the first day of drying, forage (both grass and alfalfa) conditioned by nonaggressively-set impeller machines exhibited drying rates 49 to 60% greater than the drying rates of forage conditioned by the nonaggressively-set intermeshing roll conditioner. Results also suggest that aggressively-set impeller machines, caused 1.7 to 3.4 percentage points more leaf loss than the aggressively-set intermeshing roll machine, and nonaggressively-set impeller machines caused 1.2 to 2.2 percentage points more leaf loss than the nonaggressively-set intermeshing roll machine

Midwest vision for sustainable fuel production

This article charts the progress of CenUSA Bioenergy, a USDA-NIFA-AFRI coordinated agricultural project focused on the North Central region of the US. CenUSA’s vision is to develop a regional system for producing fuels and other products from perennial grass crops grown on marginally productive land or land that is otherwise unsuitable for annual cropping. This article focuses on contributions CenUSA has made to nine primary systems needed to make this vision a reality: feedstock improvement; feedstock production on marginal land; feedstock logistics; modeling system performance; feedstock conversion into biofuels and other products; marketing; health and safety; education, and outreach. The final section, Future Perspectives, sets forth a roadmap of additional research, technology development and education required to realize commercialization

Energy Requirements for Biomass Harvest and Densification

This research quantified the unit and bulk density of several biomass crops across a variety of harvest and processing methods, as well as the energy and fuel requirements for these operations. A load density of approximately 240 kg·m−3 is needed to reach the legal weight limit of most transporters. Of the three types of balers studied, only the high density (HD) large square baler achieved this target density. However, the specific energy and fuel requirements increased exponentially with bale density, and at the maximum densities for corn stover and switchgrass, the dry basis energy and fuel requirements ranged from 4.0 to 5.0 kW·h·Mg−1 and 1.2 to 1.4 L·Mg−1, respectively. Throughputs of tub grinders when grinding bales was less than any other harvesting or processing methods investigated, so specific energy and fuel requirements were high and ranged from 13 to 32 kW·h·Mg−1 and 5.0 to 11.3 L·Mg−1, respectively. Gross size-reduction by pre-cutting at baling increased bale density by less than 6% and increased baling energy requirements by 11% to 22%, but pre-cut bales increased the tub grinder throughput by 25% to 45% and reduced specific fuel consumption for grinding by 20% to 53%. Given the improvement in tub grinder operation, pre-cutting bales should be considered as a means to increase grinder throughput. Additional research is needed to determine the energy required to grind high density pre-cut bales at high throughputs so that better estimates of total energy required for a high density bale system can be made. An alternative bulk feedstock system was investigated that involved chopping moist biomass crops with a precision-cut forage harvester, compacting the bulk material in a silo bag, and then segmenting the densified material into modules optimized for efficient transport. The specific fuel use for chopping and then compacting biomass crops in the silo bag ranged from 1.6 to 3.0 L·Mg−1 and 0.5 to 1.3 L·Mg−1, respectively. At the proposed moistures, the compacted density in the silo bags was sufficient to achieve weight-limited transport although there would be less dry matter (DM) shipped than with the high density dry bale system. Additional development work is needed to create transportable modules from the compacted silo bag. The overall results of this research will allow more accurate estimates of biomass logistics costs based on product density and energy expenditures

An Apparatus and Method for Evaluating Particle-Size Distribution of Small Grain Crop Residues

Size-reduction of small grain residue is required on the combine harvester to promote uniform distribution of residue across the full harvested width. However, unnecessary size reduction increases energy expenditures that can reduce harvester capacity. To objectively quantify the degree of residue processing, an apparatus and method was developed for evaluating particle-size distribution of small grain crop residue. The apparatus consisted of a pre-screener to sort long particles and an oscillating cascade of three screens which separated material into four additional fractions. The separation process was continuous, so large volume samples could be separated more quickly than batch systems. The developed system was used to evaluate wheat residue which was processed to various extents by a combine residue chopper in two experiments. Statistically significant (p < 0.05) differences between variably processed wheat residues were found using the developed apparatus and methodology. The separated wheat residue was partitioned into three particle-size ranges of less than 50 mm, 50 to 125 mm, and greater than 125 mm. Samples of 3 to 4 kg could be completely analyzed in less than 10 min

xPM: Enhancing Exogenous Data Visibility

Process mining is a well-established discipline with applications in many industry sectors, including healthcare. To date, few publications have considered the context in which processes execute. Little consideration has been given as to how contextual data (exogenous data) can be practically included for process mining analysis, beyond including case or event attributes in a typical event log. We show that the combination of process data (endogenous) and exogenous data can generate insights not possible with standard process mining techniques. Our contributions are a framework for process mining with exogenous data and new analyses, where exogenous data and process behaviour are linked to process outcomes. Our new analyses visualise exogenous data, highlighting the trends and variations, to show where overlaps or distinctions exist between outcomes. We applied our analyses in a healthcare setting and show that clinicians could extract insights about differences in patients’ vital signs (exogenous data) relevant to clinical outcomes. We present two evaluations, using a publicly available data set, MIMIC–III, to demonstrate the applicability of our analysis. These evaluations show that process mining can integrate large amounts of physiologic data and interventions, with resulting discrimination and conversion to clinically interpretable information

Physical Properties of Moist, Fermented Corn Kernels

A novel approach to producing corn stover biomass feedstock has been investigated. In this approach, corn grain and stover are co-harvested at moisture contents much less than typical corn silage. The grain and stover are conserved together by anaerobic storage and fermentation and then separated before end use. When separated from the stover, the moist, fermented grain had physical characteristics that differ from typical low-moisture, unfermented grain. A comprehensive study was conducted to quantify the physical properties of this moist, fermented grain. Six corn kernel treatments, either fermented or unfermented, having different moisture contents, were used. Moist, fermented kernels (26 and 36% w.b. moisture content) increased in size during storage. The fermented kernels’ widths and thicknesses were 10% and 15% greater, respectively, and their volume was 28% greater than the dry kernels (15% w.b.). Dry basis particle density was 9% less for moist, fermented kernels. Additionally, the dry basis bulk density was 29% less, and the dry basis hopper-discharged mass flow rate was 36% less. Moist, fermented grain had significantly greater kernel-to-kernel coefficients of friction and angles of repose compared to relatively dry grain. The friction coefficient on four different surfaces was also significantly greater for fermented kernels. Fermented corn kernels had lower individual kernel rupture strengths than unfermented kernels. These physical differences must be considered when designing material handling and processing systems for moist, fermented corn grain.This article is published as Blazer, Keagan J., Kevin J. Shinners, Zachary A. Kluge, Mehari Z. Tekeste, and Matthew F. Digman. "Physical Properties of Moist, Fermented Corn Kernels." Processes 11, no. 5 (2023): 1351. DOI: 10.3390/pr11051351. Copyright 2023 by the authors. Attribution 4.0 International (CC BY 4.0). Posted with permission

A Comparison of Four Mower Conditioners on Drying Rate and Leaf Loss in Alfalfa and Agrass

Mechanical conditioning of forage can be accomplished by passing the crop through fluted intermeshing rolls or by passing the crop over the tines of an impeller rotor. Three impeller conditioners and one intermeshing roll conditioner were compared in field experiments. The impeller conditioners differed on the type of tine used on the rotor. Hood position and impeller speed were the two adjustments made on all impeller conditioners. The linear load on the rolls was the only adjustment made on the intermeshing roll conditioner. The effect of the conditioning mechanisms and their adjustments on drying rate and leaf loss in alfalfa and grass crops was measured. Comparisons were made exclusively among impeller conditioners using all adjustment combinations and among all machines with specific aggressive and nonaggressive adjustments selected. In alfalfa, among impeller conditioners exclusively, the fast rotor speed caused about 7.3% leaf loss, which was 1.1 percentage point greater than the leaf loss caused by the slow rotor speed. With respect to hood position, the maximum average leaf loss was 6.77% and varied by less than 0.1 percentage point. Incidentally, in the first day of drying, alfalfa conditioned with the fast impeller speed exhibited a 3% greater drying rate constant than the drying rate constant of alfalfa conditioned with the slow impeller speed. In the first day of drying, grass conditioned with the fast impeller speed exhibited a 13% greater drying rate than the drying rate of grass conditioned with the slow impeller speed. In addition, drying rates in alfalfa varied less than 8% and drying rates in grass varied less than 10% in the first day of drying with respect to hood position. When comparisons were made exclusively among impeller conditioners, statistically significant differences in drying rate and leaf loss were only exhibited between the fast and slow impeller speeds. In the first day of drying, forage (both grass and alfalfa) conditioned by aggressively-set impeller machines exhibited drying rates 23 to 63% greater than drying rates of forage conditioned by the aggressively-set intermeshing roll conditioner. Also in the first day of drying, forage (both grass and alfalfa) conditioned by nonaggressively-set impeller machines exhibited drying rates 49 to 60% greater than the drying rates of forage conditioned by the nonaggressively-set intermeshing roll conditioner. Results also suggest that aggressively-set impeller machines, caused 1.7 to 3.4 percentage points more leaf loss than the aggressively-set intermeshing roll machine, and nonaggressively-set impeller machines caused 1.2 to 2.2 percentage points more leaf loss than the nonaggressively-set intermeshing roll machine.This article is from Applied Engineering in Agriculture 16 (2000): 1–6, doi:10.13031/2013.4984. Posted with permission.</p

Impact—Shredding Processing of Whole-Plant Corn: Machine Performance, Physical Properties, and In Situ Ruminant Digestion

An intensive processing mechanism that combined impact and shredding was applied to create physical disruption of whole-plant corn as a means to increase in situ dry matter (DM) digestion in lactating dairy cows. A ratio of treatment leachate conductivity relative to that of an ultimately processed treatment, defined as a processing level index, was used to quantify material physical disruption. Two processing levels were compared to a control treatment, which applied conventional chopping and kernel processing. The non-grain fraction was substantially size-reduced by processing such that only 28% to 51% by mass of this material remained greater than 6.4 mm length. After processing with the experimental processor, greater than 85% of kernels passed through a 4.75 mm screen, and the corn silage processing score (CSPS) was 18 to 27 percentage points greater than the control. The highly fiberized material was more compliant; thus, compacted density was 9% to 17% greater than the control. During in situ digestion experiments, processing significantly increased the rapidly soluble DM fraction by 10 percentage points and the extent of DM disappearance by 5 percentage points through 16 h incubation